1. Academy of Opto-Electronics, Chinese Academy of Sciences, Beijing 100094, China
2. Department of Applied Mathematics, University of Crete, Heraklion 71409, Greece
3. The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Applied Physics Institute and School of Physics, Nankai University, Tianjin 300457, China
4. Beijing Institute of Special Electromechanical Technology, Beijing 100012, China
5. CREOL/College of Optics, University of Central Florida, Orlando, Florida 32816, USA
6. Institute of Applied and Computational Mathematics, FORTH, 70013 Heraklion, Crete, Greece
7. Department of Physics and Astronomy, San Francisco State University, San Francisco, California 94132, USA